Optimization of controlled environment agriculture (CEA) for growing crops

Abstract

Controlled environment agriculture (CEA) is a rapidly growing production system that promotes food security, environmental stewardship, and efficient resource use. According to a recent report, global market for CEA is projected to grow at an 18.7 % annual rate and reach $172 billion in 2025. In this work, the agricultural output (crop yield and nutrient content) of three kale cultivars (‘Toscano’, ‘Redbor’, and ‘Winterbor’) grown in environmental chambers was compared with the output of identical varieties grown in the field and greenhouse systems. Differences in morphology and growth kinetics were observed between the different systems. Overall, higher phytochemical content was observed in plants from the growth chamber environment. At seedling stage, lutein concentration (macular pigment) in leaves from growth chamber was 37 – 72 % higher than lutein from other growth systems. In this study, cultivar type and developmental stage were also found to be important factors that determine nutritional quality in kale. Composition of light spectra is known to influence the morphology of plants and leaf phytochemicals. In the second study, the effect of different blue peak wavelength (400 – 450 nm) on kale development was investigated using tunable LED lamps inside CEA units. Pigment content was observed to be influenced by the type and irradiance level of blue spectrum during growth. Linear increase in lutein and chlorophyll a concentration was found as a function of blue peak wavelength. Finally, in the third study, a cost-effective spectrophotometric method for the quantification of pigments in leaf extracts was developed. Harnessing the spectral and physico-chemical properties of the principal light-absorbing compounds (chlorophylls and carotenoids) found in leafy greens, simultaneous equations were formulated and tested. Overall, the research findings will contribute to the adoption of CEA systems for growing nutritious crops.